Tank assembly for internal combustion engines



March 1, 1960 D. D. THOMAS 2,926,595

I TANK ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Filed Sept. 15, 1958 2 Sheets-Sheet 1 ZNVENTOR. .270/74/4 .25, 7ama$ March 1, 1960 D. D. THOMAS 2,926,695

TANK ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Filed Sept. 15, 1958 i 2 Sheets-Sheet 2 INVENTOR. Z7a/74Za Z 720/2745 United States Patent TANK ASSEMBLY FOR INTERNAL COM- BUSTION ENGINES Donald D. Thomas, Clinton, Mich., assignor to Clinton Engines Corporation, Clinton, Mich., a corporation of Michigan Application September 15, 1958, Serial No. 761,116

3 Claims. (21. 137-576) This invention relatesto atank assembly for use with a two cycle internal combustion engine of the .type in which gasoline and oil are mixed together and supplied to the engine. The invention is particularly directed to atank adapted to be supplied with separate quantities of fuel and oil and to thereafter effect mixing of the fuel and oil within the tank when the engine is operated.

In accordance with the present invention, the fuel tank is provided with separate fuel and oil fill portsand an oil reservoir connected to the oil fill port and extending downwardly into the tank. A combined valve and proportioning plug closes the oil reservoir during the filling operation and insures a correct fuel-oil ratio regardless of the level to which the tank may have been emptied. When the filling ports are, closed the valve automatically opens to allow oil ;to flow from the reservoir into the tank for mixture with the gasoline therein. The tank is mounted directly on the engine so as to be subject to the vibrations of the engine for effectively mixing the oil with the gasoline.

A principal object of the invention is to provide a new and improved tank assembly for a two cycle internal combustion engine.

Another object of the invention is to provide a tank assembly for a two cycle engine adapted to be supplied with separate, correctly proportioned quantities of fuel and oil and to effect mixing of the fuel and oil upon subsequent running of the engine.

A further object of the invention is to provide a fuel and oil tank of the type described having separate oil Patented Mar. 1, 1960 ticallydisposed crankshaft 16, a blower housing 18, and a carburetor 20 adapted to be supplied with a suitably proportioned mixture of gas and oil through a conduit 22 leading from the bottom of the tank 24 which is mounted on the engine 10.

The tank assembly'24 includes a cylindrical horizontally disposed tank 30 closed atits opposite ends by end plates 32 and provided in its bottom wall with an outlet receiving. afitting 34 to which the line 22 is connected for supplying the fuel-oil mixture from the tank to the carburetor of the engine.

. The tank 30 is provided with a gas fill port defined by acollar 42 suitably secured within an opening in the top of the tank 30 adjacent one end thereof. The collar 42 may be threaded or otherwise formed to detachably receive a removable gas cap 44 having a gasket 46 adapted-toflsealinglyengage the upper end of the collar 42. The tank 30"is provided adjacent its other end with a similar opening 48 within which is secured an oil reservoir 50 in the form of a hollow tube defining an oil fill port 52 at its upper end. .The oil cap 54 may be similar reservoir 50. The cap 54 is provided with threads or other provisions for detachably securing the same to the upper end of the oil reservoir tube 50.

t The tube 50 is provided at its lower end with a plate 58 having anopening 60 therein providing an outlet from the oil reservoir through which oil may flow into the tank for mixture with the gasoline therein. A combined valve and proportioning plug 62 is disposed within the oil reservoir 50 and is provided at its lower end with a valve closure member 64 engageable with the plate 58 to close the opening 60 from the oil reservoir. As shown in Fig. 4,,the plug 62 is provided between its ends with a collar 66 which may be generally square in cross section and which forms a guide for aligning the plug 62 within the reserthe collar 66 the plug 62 also has a varying cross-sec drawings, of which there are two sheets, which by way of illustration show a preferred embodiment of the invention and what I now consider to be the best mode in which 'l have contemplated applying the principles of my invention. Other embodiments of the invention may be usedwithout departing from the scope of the present invention as set forth in the appended claims.

In the drawings:

Fig. 1 discloses a perspective view of a two cycle engine having my improved fuel and oil tank assembly mounted thereon; y

Fig. 2 is a vertical sectional view through the tank assembly; t I. Fig. 3 is afview similar to Fig. 2 showing the oil and gas caps removed to permit filling of the tank; and

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3. The tank assembly of the present invention may be used with any two stroke cycle internal combustion engine and is shown in Fig. I mounted on a single cylinder air-cooled two stroke cycle engine indicated generally at 10 and including a cylinder 12, a crankcase 14, a ver- .The gas and oil caps 44 and 54 are shown in tional area to its lower end, which is provided with a series of grooves 70 to enable oil to flow around the plug 62 through the opening 60 when the valve is in its open position. a

their closed positions in Fig. 2 from which it will be seen that a valve engaging member 72 secured on the underside of the oil cap 54 engages within a recess 74'formed on the upper end of the plug 62 to force the plug 6 2 downwardly against the force of a spring 76 confined between the shoulder 66 and the end plate 58, thereby opening the valve 64 to permit oil to flow from the reservoir 50 into the tank 30. The cap 44 also carries a valve engaging member 72 so that the caps 44 and 54 may be used interchangeably on either the gas or oil fill ports.

The caps 44 and 54 are secured to the opposite ends of a bracket 80 by rivets 82 so that neither of the caps may be removed unless the other is also removed. The tank 30 is provided with aligned openings defined by the inwardly directed flanges 84, and a sleeve 86 extends centrally through the tank 30 and has its upper and lower ends suitably secured to the flanges 84. The upper end of the sleeve 86 is provided with an inwardly directed flange 88 to confine a washer 90 engaged by the upper end of a spring 92. The other end of the spring 92 engages a washer 94 seated against a shoulder 96 formed on the lower end of a rod 98 which extends upwardly through the washer 90 and through a hole 100 in the bracket 80. The upper end of the rod 98 is provided with a head 102 engaging the upper surface of the bracket 80.

3 The spring 92 urges the rod 98 and the bracket 80 down wardly toward the tank and maintains the caps 44 and 54 in sealing engagement with the fill openings. V When it is desired to fill the tank with g asand oil, the caps 44 and 54 are both loosened from their respective fill ports and the bracket 80 may then be lifted in the manner shown in Fig. 3 to lift the closure caps to a height sufiicient to permit the bracket 80 to be rotated on the rod 98 to swing the caps away from their fill ports and allow filling of the latter with gas and oil. When the caps are removed the spring 76 will urge the plug 62 upwardly to engage the valve 64 with the lower end of the oil reservoir to close the opening 60 therein. The tank 30 may then be filled with gas and the oil reservoir 50 filled with oil. The volume of the reservoir 50 with the plug 62 therein is such as to give the correct fuel-oil ratio for proper engine operation. The oil can flow past the upper end of the plug 62 across the flats defined by the squared upper end of the plug, and also through one or more passages 104 leading from the recess 74 through the plug 62. After the tank and the oil reservoirhave been filled with gas and oil, respectively, the caps 44 and 54 are re-' placed, causing opening of the valve 64 to enable oil .to flow from the reservoir into the tank.

As shown in' Fig. l, the tank assembly 24' is mounted directly on the engine in any suitable manner such as by the use of supporting brackets 110 so that the tank and its contents will be subjected to engine vibrations which are relied upon to etfect thorough mixing of the 'oil and gas within the tank. The oil, being heavier than gasoline, will, of course, tend to flow through the outlet 69 from the reservoir to facilitate mixing of the oil and gas.

In the illustrated embodiment of the invention the oil reservoir tube 50 is cylindrical and of uniform crosssectional area throughout its height, while the proportioning plug 62 has a variable cross-sectional areathroughout its height. insure that the ratio of the quantity of oil receivable in the tank Sll to the quantity of gasoline inthe tank 30 will be substantially constant regardless of the levelto which'the tank may have been drained by previous engine operation; Since the tank 30 is cylindrical and'horizon' tally disposed, it will be apparent that the tank can receive progressively larger quantities of gasoline per unit of height as the tank is filled up to the half-full level and) will be filled with progressively smaller quantities of gas per unit of height as it is filled from the half full level to full. The proportioning plug 62 is designed toco'mpensate for the variation in the horizontal cross-sectional area of the tank at different levels thereof so that, regardless o f-the extent towhich the tank may be filled with afuel-oil mixture, the correct ratio of oil to fuel will be maintained as long as the oil and gas are filled to the same level within the reservoir 50 and tank 30', re spectively.

A tank assembly in accordance with the present invention possesses many advantages for use with a two cycle engine and, in particular, eliminates the need for preliminary mixing of the oil and gas in aseparate contamer as has been the usual practice heretofore. The

oil reservoir and its proportioning plug are shaped to insure a substantially constant ratio of oil to gas without:

the necessity for measuring the separate quantities of oil and gas other than to fill the same to the same level within their respective containers. In addition, the arrangement of the oil and gas closure caps and the connection thereof The purpose of such construction is to with the tank requires both fill ports to be opened at the same time, thereby reminding the operator to fill the tank with oil as well as gas. With this arrangement the closure caps are permanently connected to the tank so that they cannot become lost or mislaid during a filling operation. An additional advantage of this construction is that it is not necessary that the caps have a threaded connection 'with their fill ports because the caps are always nrged to their closed position, and therefore a simple spring or detent connection between the caps and their fill ports may be used, although a threaded connection may also be used if desired.

While I have illustrated and described a preferred embodiment of my invention, it is understood that this is capable of modification, and I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim: Y t V g 1 In a two cycle internal combustion engine, a tank from which a mixture of gas and oil is supplied to the engine, comprising a cylindrical horizontally disposed tank having an oil fill port and a gas fill port therein, an oil receiving reservoir having an opening at its lower end and extending from said oil fill port downwardly into said tank, a combined valve and proportioning plug in said reservoir, valve means on said plug for closing the opening in said reservoir, spring means urging said plug up-. wardly to close said opening, a removable cap for said oil fill port, said cap having means engageable with said plug to force the latter downwardly to uncover the opening in said reservoir 'when said cap is in place on said oil fill port, thte' cross-sectional area of said plug being different from that of said reservoir throughout its height whereby the ratio .of the quantity of oil receivable in said reservoir to the quantity of fuel receivable in said tank is substantially constant regardless of the level of the fuel-oil mixture in the tank. r i t v 2. A' tank assembly for a two cycle internal combustion engine adapted to receive and to mixseparate quantities of fueland oil and from which a mixture of fuel an d oilis supplied tothe engine, comprising a tank haviiig different cross-sectional areas at diiferent levels there:

of, said tank having an oil fill port and a fuel fill port a said tank, a combined valve and proportioning plug in said reservoir, said plug having a closure member on its: lower end for closing the lower end of said reservoir, spring means urging said plug upwardly to close the lower end of said reservoir, a removable cap for said oil fill port, said cap being engageable with said plug to force thelatter downwardly to open said reservoir when said cap is in place on said oil fill port, said reservoir and said plug being shaped so that the ratio of the quantity of oil receivable in said reservoir to the quantity of fuel re ceivable in said tank is substantially constant regardless of the level of the fuel-oil mixture in the tank.

3. A tank assembly according to claim 2 including a,

removable cap for said gas fill port, a bracket to which both said removable caps are connected whereby both caps must be removed to open either fill port, and means movably connecting said bracket to said tank.

References Cited in the file of this patent UNITED STATES PATENTS 2,405,442 Mayo Aug. 6,1946 

